My Singer 2000's red circuit breaker button will not stay engaged?

The lights turn on, I can change the patterns and stitch length on my Singer 2000 Touch Tronic but the needle is stuck so that when it is lowered it hits the plate. The instruction booklet suggests pushing the red circuit breaker button which I have done, but it will not stay in as it is supposed to. Is there anything I can do to fix my machine? I am very handy but because of my machines age I am afraid to open it unless I have some idea of what I should look for.

Thanks for any help.